Preheat oven to 375 degrees
Toss hericots verts in olive oil, salt and pepper
Spread mustard over salmon
Transfer hericots verts and salmon onto piece of foil and cover salmon with another piece of foil to make a packet
Bake for 14 minutes
Optional: Turn broil on high and uncover salmon, broil for 2 minutes
Top with green onions
Enjoy!